Beijing has protested the repair and upgrade of military facilities on Thitu Island, or Pagasa Island, in the South China Sea.

The Armed Forces of the Philippines (AFP) has started concreting and upgrading the airstrip on Pagasa Island, extending the more than a kilometer runway, which was neglected for such a long time that the edge has been eroded.

International news agencies reported that China’s Defense ministry spokesman Tang Kefei said Beijing was “resolutely opposed” to any Philippine development on Thitu.

“China’s military will unswervingly safeguard national territory, sovereignty and maritime rights, while resolutely maintaining peace and stability in the South China Sea,” he said, without elaborating.

The Philippines ignored China’s protest, but fired another diplomatic protest after Beijing deployed several vessels around the 37-hectare land feature in the Spratly, the main military facility in the South China Sea.

The “swarming” presence of Chinese ships was Beijing’s way to pressure Manila to stop its construction activities on Pagasa Island.

This was the first time China lodged a protest, an indication that the frenzied activities of the Philippine military in the disputed waters were getting noticed.

Manila has also increased its maritime patrol activities in the West Philippine Sea, driving away China’s militia ships from Sabina Shoal not just once but twice. It was the closest China could come near mainland Palawan.

China could be attempting to seize control of four strategic land features which are closer to Palawan, expanding its claims and encroaching deeper into the country’s sovereign waters.

These are Sabina Shoal, Boxall Shoal, Amy Douglas Shoal and Half Moon Shoal. It is interesting that Half Moon Shoal, only about 100 nautical miles from Palawan, is a known illegal trading post of local fishermen selling giant green sea turtles and other endangered species to Chinese traders.

A Chinese frigate had run aground in its shallow waters many years back, raising alarm bells in Camp Aguinaldo which sent out patrols in that area.

Unluckily, one of the ex-US Coast Guard USS Hamilton-class weather high endurance cutters (whec) also ran aground in that area, indicating that the shallow waters around Half Moon Shoal are really dangerous for maritime shipping.

Three years ago, China sent dozens of ships near Pagasa Island when the military started building a beach ramp to allow large vessels to deliver construction materials and rehabilitate structures, improve the airstrip, and build other facilities, like communications and navigational aids.

As far back as 2011, Lt. Gen. Roy Devenaturda, then commander of the Western Command, unveiled a P500-million development plan to fortify Pagasa and eight other land features the Philippines occupied in the Spratly Islands.

Three of the territories were half-submerged during low tide and completely under water during high tide. The Philippine facilities are on stilts, similar to the Badjao houses in Tawi-tawi.

The Western Command also planned to build a naval base in Balaback and revived an old American airstrip in southern Palawan as an alternate air force base.

General Devenaturda’s plan came even before China started building the great wall of sands in the Spratly Islands, transforming small reefs and shoals into artificial islands and installing surface-to-air and shore-to-ship missiles to protect the garrisons.

The Philippines and other Southeast Asian countries with competing claims in the South China Sea — Brunei, Malaysia and Vietnam — had also protested China’s excessive land reclamation and island building.

Other members of the Association of Southeast Asian Nations (Asean) joined in the protest, through annual statements made during summit meetings in various Southeast Asian capitals.

But China ignored all of them, including statements made by the United States and other Western countries.

The Philippines postponed all its development projects in the South China Sea after Manila filed an arbitration complaint against China before the Permanent Court of Arbitration in The Hague in 2013.

The government of then-president Benigno Aquino wanted to take the moral high ground by stopping any activity in the disputed sea, including the private sector-led oil-and-gas exploration in the Reed Bank.

Only the development of a naval operating base in Ulugan Bay in western Puerto Princesa area, known as Carlito Cunanan base, continued, with the Department of Public Works and Highways (DPWH) constructing an access road to the naval base and cutting into the virgin forest in western Palawan.

The navy planned to replicate the Subic naval base in Ulugan Bay but on a much smaller scale, as the mouth to the bay was so narrow that the US Navy’s Aegis guided-missile Arleigh Burke-class destroyer would not be able to clear the entrance to the protected cove due to its nine-meter draft.

For smaller frigates, there would be no problem but the limited space could accommodate only four to five frigates at the same time.

In July 2016, the Philippines won a landmark arbitral ruling from The Hague, which nullified China’s excessive and illegal nine-dash-line claims in the South China Sea.

That could have been the signal for the military’s massive buildup to strengthen its claims in the South China Sea as well as improve the long-neglected military structures in Pagasa and eight other areas.

But President Rodrigo Duterte would have none of those grand projects. He was too concerned with what China would feel and say about the military development projects as he eagerly pivoted the country’s foreign policy toward Beijing in the hope of winning billions of investments, trade, and official development assistance funds.

However, only 5 percent of the $24-billion investment pledge made by China in 2016 was realized five years into his presidency. And China is now hedging to commit funds as he nears the end of his six-year single term.

Even the development of Ulugan Bay naval base came to a halt after the US reportedly crafted a plan to relocate a marine jungle training base in Palawan.

But Defense Secretary Delfin Lorenzana silently worked to upgrade the facilities in the Spratly and Duterte was forced to go along with it after the military presented him development plans during one of his early visits at Western Command headquarters in Puerto Princesa. It was unclear if the US plan to construct facilities under the 2014 Enhanced Defense Cooperation Agreement (EDCA) had pushed through in 2018.

The beach ramp was the start but more joint civilian-military use projects, like lighthouses and navigation aids, a water desalination plant, and communications facilities were put up.

Also, P9 billion in fisheries, environment, and eco-tourism projects were planned in the Kalayaan Group of Islands, a town under Palawan which covers the areas claimed by the Philippines in the Spratly Islands.

As the Philippines started to implement these civilian-military projects as well as increase naval and law enforcement patrols in the Spratly Islands, China started to take notice.

The Chinese defense ministry’s protest last week will certainly not be the first and last as it seeks to assert its own claims.

Harry Roque, the president’s spokesman, was trying to play down simmering tensions between the Philippines and China in the South China Sea.

But he could not deny that the rhetoric on both sides would rise and escalate further as the Philippines carries out its ambitious development plan.

The Philippines must also build lighthouses and other aids to navigation to assert its claims in the South China Sea. These structures are civilian in nature and are not confrontational, which all claimant-states would readily welcome given the dangerous waters around the disputed sea.

The country could start by putting lighthouses, which are also cheaper investments, in Amy Douglas Shoal, Boxall Shoal, Half Moon Shoal and Sabina Shoal because China has started visiting these areas, hoping to gain control of them like what it did in Scarborough Shoal in 2012.

The Philippines can prevent this by putting up lighthouses, which can become the country’s symbol of sovereignty.

The Philippines cannot match the large number of naval and civilian vessels that China deploys in the South China Sea, which helps control the seas, but the country can fight back and assert its claims by building cheap lighthouses on uninhabited land features in the disputed sea.